1. FIELD OF THE INVENTION:
The invention relates in general to abrasive entrained high pressure fluid jet apparatus for cutting and removing pavement and in particular to a highly maneuverable, mobile apparatus having a means for moving one or multiple abrasive entrained high pressure fluid jet nozzles in both the horizontal and transverse directions and a means for rotating the one or multiple fluid jet nozzles to provide for scarifying large sections of pavement, removing large sections of pavement, or cutting a large circular perimeter of pavement to provide for removing manhole type portions of pavement.
2. DESCRIPTION OF THE PRIOR ART:
In populated areas, there are many miles of utility distribution systems. These systems include electrical power and communication cables, water and gas distribution piping systems, sewers, and other special cables, pipes and conduits. Many of these utility systems must be buried underground for aesthetic, protective, and other reasons; they are often buried under streets or other paved areas. Thus, the installation or servicing of utility systems frequently requires excavations to gain access. The first step of such excavations, which are generally in the form of a "manhole" or short trench, is to cut and remove the pavement delineated for excavation. Subsequently, the earth is removed to expose the buried utility systems or to form a trench for installing new systems.
The common tools involved today in manholing, trenching, or patching pavement are saws, handheld jackhammers, backhoes, and trenchers. In case of asphalt pavement, jackhammers or backhoes can be used to break the pavement although the edges of such excavations are very ragged unless saws are used to cut the perimeters. In case of concrete, diamond studded concrete saws are required to first cut the perimeter of a manhole or a trench to a desired depth. Subsequently, jackhammers are used to break the patch or the strip of concrete between two parallel cuts. These conventional approaches of excavation have many drawbacks that contribute to the high cost of such operations. The handheld pneumatic/hydraulic hammers are known to be very slow, noisy, and fatiguing to the operators. These hammers also cannot produce clean edges or avoid the fracture of adjoining concrete, causing the pavement patches to lack permanency. Concrete saws have drawbacks in slow speed of operation, noise generation, need for overcutting at corners, and high cost due to the excessive wear and tear of the saw blade. Finally, the conventional process of removing pavement requires the use of several pieces of equipment and many operators.
Accordingly, it would be desirable to have an abrasive entrained high pressure fluid jet apparatus which is both highly maneuverable and mobil for cutting and removing pavement. Further, it would be desirable if such apparatus had a means for manipulating one or more abrasive entrained high pressure fluid jet nozzles in both the horizontal and transverse directions so as to be able to cut a path of any design for the removal of pavement. A means for rotating such multiple high pressure fluid jet abrasive entrained nozzles would be desirable to provide for scarifying large areas of pavement, cutting a circular perimeter around a predetermined portion of pavement, (such as for the removal of a manhole of pavement) and cutting large diameter holes in pavement.